Thunderbird 900 Rear Suspension, Swap For Kawasaki Zx7?

dearborn

Active Member
Local time
Yesterday, 21:31
Joined
Sep 29, 2015
Messages
111
Points
27
Age
70
Location
Dearborn Michigan USA
First Name
Doug
My Ride
1996 Thunderbird, 1975(ish) Norton Commando
Lots of talk here on this; So, I Ebay-ed a used Kaw ZX7 rear shock with the link, "dog bones" and hardware to replace the very harsh stock unit on my 1996 Thunderbird. I also scored for $20 two really nice, used, adjustable, aftermarket alloy lowering "dog bones" for ZX7 with a spread of 3 mounting holes that look like they will compensate for the raised ride height. Yes, the Kaw shock is longer than the Triumph unit. Mounting the shock to the stock Triumph link raises the rear ride height about an inch or more if the stock Triumph "dog bones" are used. A couple of observations; The Kaw link is shorter than the Triumph link. Using the Kaw link MAY also make up for some of the raised rear ride height. The stock Kaw dog bones are also longer than the Triumph ones. The aftermarket lowering dog bones are pretty common Ebay items and should do the trick, allowing for about 2in. of adjustment. The Kaw link also does NOT have the zerk fitting for greasing the needle bearings on the pivot though it does have an undrilled boss on the casting that should be easy to drill & tap for the grease fitting. The spring on the Triumph shock is shorter and made from a heavier gage wire than the Kaw spring indicating that the criticism of the Kaw spring being too soft is likely correct. The length of the threaded area on the Kaw shock looks long enough to swap out the spring from the Triumph unit if desired. I have not ridden the bike yet after swapping the shock. My questions to those who have played around with this are; What did you use to mix&match this stuff and how did it affect rear suspension geometry, ride and handling? We're having a heat wave here in Detroit- upper 40s!!! no snow!! so road testing is possible. Will try out different combinations this week and report back.
 

Gogreen

Member
Riding for 46 Years
Local time
Today, 02:31
Joined
Jul 2, 2015
Messages
40
Points
7
Location
UK
First Name
Phil
My Ride
Thunderbird Sport; T140D
Hmm interesting. Just to confirm was the doner an ZX7 or a ZX7R, the ZX7 is a budget machine and has budget suspension; the most common moan of ZX7R owners is the harsh rear suspension. I find the stock Triumph shock OK, if yours is harsh (and by harsh do you mean over-damped or over-sprung, or both) back off the preload (and damping if adjustable) and check the linkages are all free and lubricated. The Tbird is long and steers relatively slowly so although jacking up the rear will speed up steering response I doubt if it would be skittish and need damping. lowering is a personal choice but never improves handling, or anything else that I can understand. My exhausts and pegs ground with stock ride settings.
Its 40deg here too (4 degC ) wet and windy
 

dearborn

Active Member
Local time
Yesterday, 21:31
Joined
Sep 29, 2015
Messages
111
Points
27
Age
70
Location
Dearborn Michigan USA
First Name
Doug
My Ride
1996 Thunderbird, 1975(ish) Norton Commando
Mistake #1; The conversation about this was on Triumph RAT forum, not here. I find that forum to be a PIA to use, so don't visit often, prefer this forum. There was a lot there about this topic. ZX7R shock has a reservoir that sticks out too far and won't fit UNLESS you use the one with a hose leading to the reservoir which can be mounted in the location you find works for you. I have the 1993 ZX7 item WITHOUT the attached reservoir. The other forum has folks who have used ZX6, ZX7, ZX9 and ZX11 shocks with varying results, with the ZX7 item being the most widely used. The "lowering" dog bones I referred to were intended to compensate for the increased length of the ZX7 shock which raised the ride height of the rear of the bike and were intended to "lower" the bike's rear back to standard ride height. The roads here in S.E. Michigan are mostly long and straight and in horrible condition; frost heaves, patches, disintegrating concrete, etc, some of the worst in USA. Loose gravel, sand, hot weather tar snakes from road patches, damage from snow plows, etc, make leaning this bike over far enough to scrape foot rests and exhaust pretty rare and dangerous, at least for about 200 miles in any direction. Hitting sharp edged bumps and pot holes on this bike feel like your spine is driven right up into your skull. (My much modified Norton Commando with the USA made Mulholland twin rear shocks rides MUCH better on bumpy roads than the 1996 Thunderbird!) On the rare stretches of smooth pavement, the bike is Ok for an hour or so; freeway drones, etc. All pivot points, needle bearings, etc, are in good condition and well lubricated. The original Triumph shock visually appears to be in good condition; no sign of leaks, appears to be in operating condition when "bench testing" The harsh ride seems to be a very common complaint. Why try the Kawasaki shock? Quoted prices for aftermarket replacements from HAGON, etc, for the T-Bird range in price from $500-$600 up to $1200+ Cost for used Kawasaki shock? $40! plus extra $20 for the polished alloy used lowering dog bones. Well worth a bit of experimenting. I traded a 1973 Triumph 500 T100R with a very tired bottom end for the Thunderbird which had some minor L/H side damage from a very low speed tip over and short slide. I had always wanted one and had worked as a mechanic in local Triumph dealer in 1995/96, so I am familiar with them. Intention was to fix and flip it and make a few $$$ to put toward a new bike, but the more I rode it, the more I liked it. Have not been able to road test after swap; rain and freezing temps. last few days, waiting for dry weather.
 

dearborn

Active Member
Local time
Yesterday, 21:31
Joined
Sep 29, 2015
Messages
111
Points
27
Age
70
Location
Dearborn Michigan USA
First Name
Doug
My Ride
1996 Thunderbird, 1975(ish) Norton Commando
Kaw shock is about 14mm longer; raises rear ride height about 1-2 inches using Triumph link and dog bones. (Stupidly, I didn't measure ride BEFORE changes) Also why use Kaw shock? Kaw shock is rebuildable, Triumph is not
 

dearborn

Active Member
Local time
Yesterday, 21:31
Joined
Sep 29, 2015
Messages
111
Points
27
Age
70
Location
Dearborn Michigan USA
First Name
Doug
My Ride
1996 Thunderbird, 1975(ish) Norton Commando
I have a standard Thunderbird, NOT a Sport, so stock rear shock is not adjustable other than pre-load on spring. Finally was able to ride it today, about 50 miles, with stock shock. HORRIBLE! Harsh. Playing with pre-load does not help at all. Ebay Kawasaki ZX7 shock I bought was a bad buy; nitrogen had leaked out and action is rough. Drained old oil; stinky, black, nasty stuff smelled like old fish! Flushed out and refilled with BMW 7.5wt front fork oil. A THOROUGH internet search turned up almost zero info on the Kaw shock. No specs found for capacity, oil recommendation or viscosity, zero listings found for parts for ZX7, (seals, etc), zippo anywhere. Triumph RAT forum conversations, (do NOT like using RAT forum, PIA to use, slow), had a number of post on this using different oils and using plain air at high pressure with good results. So, I had the BMW oil on the shelf and used that. Removed spring, bled off any remaining pressure, drained and flushed oil, collapsed shock to shortest length and filled with as much oil as it would hold pumping it a bunch of times to bleed out trapped air and managed to get about 175psi of air in it. (Posts mentioned 145psi nitrogen, 175-250 psi air) Well, it felt OK, no sign of leaks found by submerging in water for extended periods, but after a few days checked action by trying to compress it by hand and feels like it has lost air. Can compress it with a bit of force pressing against side of bench. Air had leaked down to about 60psi. There are YouTube tutorials on stripping and rebuilding similar shocks, but I can't find a parts listing anywhere, including RaceTech. So that's where it's at. If I can find parts or another shock that works, it is a decent alternative to spending $$$$$$$ on an aftermarket shock. But, no parts as yet.
 

Gogreen

Member
Riding for 46 Years
Local time
Today, 02:31
Joined
Jul 2, 2015
Messages
40
Points
7
Location
UK
First Name
Phil
My Ride
Thunderbird Sport; T140D
This of a Suzuki site, may help!
Good luck

Make Model Year Shock Length(mm) Shock Stroke(mm)
Suzuki Bandit 600 2000-2004 319 55
Suzuki Bandit 650 2005 319.5 65.5
Suzuki Bandit 1200 1996-2000 306 64
Suzuki Bandit 1200 2001-2005 320 (+6/-0) 61
Suzuki GSXR 600 1992-1993 312 (+12/-0) 67
Suzuki GSXR 600 2001-2003 325.5 (+6/-0) 74
Suzuki GSXR 600 2004-2005 332.5 (+6/-0) 74
Suzuki GSXR 750 1985-1987 290.5 61
Suzuki GSXR 750 1988-1991 312 (+12/-0) 67
Suzuki GSXR 750 1992-1995 312 (+12/-0) 67
Suzuki GSXR 750 1996-1999 356 (+6/-6) 79
Suzuki GSXR 750 2000-2003 325 (+6/-0) 74
Suzuki GSXR 750 2004-2005 332.5 (+6/-0) 74
Suzuki GSXR 1000 2001-2002 329.5 (+5.5/-0.5) 74
Suzuki GSXR 1000 2003-2004 332.5 (+6/-0) 74
Suzuki GSXR 1000 2005 319 70
Suzuki GSXR 1100 1986-1988 315 69
Suzuki GSXR 1100 1989-1992 312 70
Suzuki GSXR 1100 1993-1998 312 70
Suzuki Hayabusa 1999-2006 330 72
Suzuki SV1000/SV1000S 2003-2007 3325
Kawasaki ZX6R 2003-2004 340 (+12/-0) 72.5
Kawasaki ZX6RR 2003-2004 340 (+12/-0) 72.5
Kawasaki ZX6R 2005 335.5 (+12/-0) 64.5
Kawasaki ZX6RR 2005-2006 330 (+12/=0) 63.5
Kawasaki ZX7R 1996-2001 350 (+12/-0) 75
Kawasaki ZX9R 1994-1997 348 79
Kawasaki ZX9R 1998-1999 330 (+12/-0) 69
Kawasaki ZX9R 2000-2001 338 67
Kawasaki ZX9R 2002-2003 338.5 67.5
Kawasaki ZX10 1988-1989 314.5 67
Kawasaki ZX10R 2004-2005 338 (+7/-5) 69
Kawasaki ZX12R 2000-2005 338 (+7/-5) 67
Honda CBR 600 F 1987-1990 292 50
Honda CBR 600 RR 2003-2006 313 (+0/-6) 59.5
Honda VFR 800 FI 1998-2001 325 58
Honda VFR 800 FI 2002-2005 317.5 53.5
Honda CBR 900 RR 1992-1995 319 (+12/-0) 54
Honda CBR 900 RR 1996-1997 305 (+12/-0) 60
Honda CBR 900 RR 1998-1999 303 (+12/-0) 57
Honda CBR 900 RR 2000-2001 286 (+4/-2) 57
Honda CBR 900 RR 2002-2003 288 (+2/-4) 57
Honda CBR 929 2000-2001 286 (+4/-2) 57
Honda CBR 954 2002-2003 288 (+2/-4) 57
Honda RC51 2000-2005 326 (+10/-2) 63
Honda CBR 1000 RR 2004-2006 314 (+6/-0) 58
Honda VTR 1000 F 1997-2005 346 60
Honda VTR 1000 SP1 2000-2001 326 (+10/-2) 63
Honda VTR 1000 SP2 2002-2005 326 (+10/-2) 63
Honda CBR 1100 XX 1997-2005 319 52
Yamaha YZF 600 1994-1999 360 (+12/-0) 70
Yamaha YZF R6 1999-2002 305 (+4/-2) 62
Yamaha YZF R6 2003-2004 295 (+5.5/-0.5) 62.5
Yamaha YZF R6 2005 300 (+0/-6) 62.5

Yamaha FZR 750 1987-1988 300.5 54
Yamaha FZR 750R 0W01 1989-1991 360 76
Yamaha FZR 1000 1987-1988 300.5 54
Yamaha FZR 1000 1989-1995 340 70
Yamaha YZF 1000 1996-2000 340 (+12/-0) 69
Yamaha YZF R1 1998-2001 300 (+11/-1) 65
Yamaha YZF R1 2002-2006 300 (+5.5/-0.5) 64.5

k9/k10 GSXR 1000 315mm ETE 67mm stroke oem spring 11.6 (kg / mm) = 649.570009 pounds / in
 

dearborn

Active Member
Local time
Yesterday, 21:31
Joined
Sep 29, 2015
Messages
111
Points
27
Age
70
Location
Dearborn Michigan USA
First Name
Doug
My Ride
1996 Thunderbird, 1975(ish) Norton Commando
THANKS! So today I had a long talk with RaceTech. Guy was VERY helpful. Explained functions and problems with various types of shocks. Said these shocks were never meant to be rebuilt, only tossed when bad. Kawasaki does NOT sell any parts for them and RaceTech's parts coverage is limited. He said that for my ZX7 shock, he could supply a few of the seals, etc, but if it wasn't leaking oil, only air/nitrogen pressure, I would probably just be wasting my money as the leaks was likely coming from 2 places; the Schrader valve or from the seal on the shaft of the adjuster knob on the bottom of the shock and no, that part is not available ANYWHERE. I took the internal assembly out and cleaned it, (simple snap ring), and attempted to take the nut on the end of the shaft off for access, but just as he warned, the threads on the shaft started to come with it. The bushing seemed to be in good shape so a trip to the old time hardware store and a bit of time with the caliper and some rooting around in the massive O ring assortment turned up 2 that matched; the large one on the piston and the small one on the Schrader valve where it attaches to the shock body. RaceTech guy also said 5wt to 10wt fork oil is good as is my 175psi of air. So reassemble, new O rings, new oil and a trip tomorrow to the local dirt bike shop for a nitrogen refill at the correct pressure as I lose too much when disconnecting my air chuck. If it still leaks pressure, I've only lost about $40 so I'll toss it and buy another off Ebay from a low miles bike and try again. Maybe go for one with a remote reservoir and more adjustment. Even with a slow pressure leak, the remote reservoir would allow for a quick top-off of air before a ride. Just can't see dropping $500-$1200 for a shock on a bike that's only worth maybe 2 grand or so.
 

dearborn

Active Member
Local time
Yesterday, 21:31
Joined
Sep 29, 2015
Messages
111
Points
27
Age
70
Location
Dearborn Michigan USA
First Name
Doug
My Ride
1996 Thunderbird, 1975(ish) Norton Commando
Thunderbird/Kawasaki shock swap, Act 2,; ZX7 shock will not hold air pressure, no parts available, so off it goes, re-install crappy hardtail ride original shock, (150+ mile ride this Sunday!), and order a '94 thru '97 ZX9 shock with the remote reservoir on a hose, used, off Ebay . For this one, you can get parts from RaceTech and other sources; I checked! Thanks to the info provided by Phil, looks like the overall length is closer to the original Thunderbird shock than the ZX7 I was experimenting with. Waiting eagerly for the postman.
 

dearborn

Active Member
Local time
Yesterday, 21:31
Joined
Sep 29, 2015
Messages
111
Points
27
Age
70
Location
Dearborn Michigan USA
First Name
Doug
My Ride
1996 Thunderbird, 1975(ish) Norton Commando
UPDATE; Well, more problems! Ebay ZX9 shock won't hold nitrogen pressure. Turns out KBY-Kayaba Kaw ZX9 shock with remote reservoir on a hose parts are maybe/maybe NOT available either. There are lots of parts available for dirt bike applications for these KYB-Kayaba shocks, and some available for the SHOWA units used on other bikes, BUT, the street bike applications were NOT meant to be rebuilt! Just toss 'em a when they fail and fork over $500-$1200 for an aftermarket unit. However, the design is identical to the dirt bike unit, only dimensions like length, spring, shaft diameter, etc, are variable. The '94 Kaw ZX9 shock I bought off Ebay is different than the ZX9R unit in that the ZX9R unit has the reservoir attached to the shock body and it juts out from the top at about a 45 deg. angle which makes it difficult to use on the Triumph Thunderbird without modifications to the battery box, etc. Long conversation with very helpful guy at RaceTech, "Brad", while measuring various components resulted in a "Try these and see if they work" selection of seals and a bladder. Waiting for the postman.
 

dearborn

Active Member
Local time
Yesterday, 21:31
Joined
Sep 29, 2015
Messages
111
Points
27
Age
70
Location
Dearborn Michigan USA
First Name
Doug
My Ride
1996 Thunderbird, 1975(ish) Norton Commando
UPDATE; Well, more problems! Ebay ZX9 shock won't hold nitrogen pressure. Turns out KBY-Kayaba Kaw ZX9 shock with remote reservoir on a hose parts are maybe/maybe NOT available either. There are lots of parts available for dirt bike applications for these KYB-Kayaba shocks, and some available for the SHOWA units used on other bikes, BUT, the street bike applications were NOT meant to be rebuilt! Just toss 'em a when they fail and fork over $500-$1200 for an aftermarket unit. However, the design is identical to the dirt bike unit, only dimensions like length, spring, shaft diameter, etc, are variable. The '94 Kaw ZX9 shock I bought off Ebay is different than the ZX9R unit in that the ZX9R unit has the reservoir attached to the shock body and it juts out from the top at about a 45 deg. angle which makes it difficult to use on the Triumph Thunderbird without modifications to the battery box, etc. Long conversation with very helpful guy at RaceTech, "Brad", while measuring various components resulted in a "Try these and see if they work" selection of seals and a bladder. Waiting for the postman.
UPDATE;
If you buy a used X7 shock, (Ebay, salvage yard, etc), and it leaks oil or nitrogen charge, GOOD LUCK finding ANY service parts! If you get one that is in good working order, it's EASY to swap for the stock one and IS quite an improvement. It will very quickly point out the need to upgrade the FRONT!
In any case, the 1994 thru 1997 ZX9 shock, the one with the reservoir on a hose is the one to find. If it DOES leak, replacement bladders are about $20 and some of the seals and bushings are available. YouTube "how to" videos will show how to service them. It is EXTREMELY critical, though to NOT mix up the shim packs or their order or orientation. Or the valve. Dirt bike guys play around with the shim packs for specific performance gains, but DON'T DO IT!! ask me how I know!
 

dearborn

Active Member
Local time
Yesterday, 21:31
Joined
Sep 29, 2015
Messages
111
Points
27
Age
70
Location
Dearborn Michigan USA
First Name
Doug
My Ride
1996 Thunderbird, 1975(ish) Norton Commando
SUCCESS!!!!
200+ mile ride to AMCA Wauseon meet Saturday. Result? Much improved ride, now playing around with adjustments; spring pre-load, rebound damping and compression damping. It is extremely easy to swap the rear shock on these bikes. My recommendations if you want to try this, (and save a pile of $$$ over buying an aftermarket shock); I used a 1994 thru '97 Kawasaki ZX9 shock. You want the one with the reservoir on a hose, NOT the one with the reservoir sticking out at about a 45deg angle as that will NOT fit without a LOT of modification to the battery box, etc., and simplicity is where I'm at. These used shocks sell on Ebay for around $20 to $100 or so. A cheap one may have leaks; usually won't hold the nitrogen charge. If it is really dirty, it may have oil leaks or the bike it came off of had crappy maintenance and spewed oil. Parts for these things are really hard to find and not all parts are available. RaceTech will sell you a new bladder, a dust seal and 1 oil seal for the piston. These fixed my leaks for about $40 as I recall. I had some BMW 7.5 wt front fork oil on the shelf, it worked fine, RaceTech will sell you a bottle of their oil for about $20, which I'm sure works great. So, buy a cheap one that may need rebuilding, or a more expensive one that may not need any work. The oil that came out of the three I bought, (a ZX7, ZX9 with the hose and a ZX9R), for comparison was FILTHY!!!, so I would definitely recommend a drain, clean and refill with fresh oil so that means you're taking it partially apart.
Before you attempt to do anything, RELEASE THE PRESSURE AT THE SCHRADER VALVE!! Hold a rag over this while you're releasing the pressure because oil will squirt all over the place!.
There are tutorials on YouTube for this; watch them all. Cleanliness is extremely important! It's pretty simple to service these things, replacing the bladder is pretty straightforward. BUT.... To change the oil, you have to open the body of the shock. If you are replacing any of the seals, bushings, etc,. you will have to take the assembled shaft apart. Once inside, you will have to grind off the top of the nut on the shaft. DO NOT let debris fall down inside the shaft! Plug it with grease which you can wash out after you're done and blow it out thoroughly with compressed air. CAREFULLY remove the nut. IMPORTANT!!!! DO NOT LOSE THE ORDER AND ORIENTATION OF THE MANY TINY SHIMS!! If you mess this up, you are screwed!! You will now be able to replace the dust seal and the oil seal in the piston. Do NOT lose the orientation/position of the piston!!! Mark the "up" side of everything with a paint dot. Reassemble the shaft, thoroughly clean everything. Use high strength Loctite on the threads on the retaining nut and tighten securely, (could not find torque spec on this), let cure overnight.
Slightly loosen the hose at the reservoir which is running at roughly a 90deg. angle and adjust the hose to run in line with the reservoir. Slightly loosen the hose at the shock body and rotate it to point down toward the spring as much as possible without fouling the pre-load adjuster rings. Tighten both ends securely.
Fill the reservoir with oil, install the new bladder, making sure the retainer ring is seated in its' groove securely, reinstall the core in the Schrader valve and add a couple psi of air. Next, holding it in your vise, fill the shock body with oil to within about an inch of the top and install the shaft assembly. (Are you sure you didn't mess up the shim packs? Sure the piston is right side up?)
You will lose oil, don't make a mess. The idea is to thoroughly fill the shock, hose and reservoir with no air.
Be sure to re-install the retaining ring in the BOTTOM GROOVE!
Tap the alloy cap back in place.
Do not re-install the spring yet, so you can check it's operation after you take it to the local dirt bike shop for a recharge. They charged me $20 to fill it. Without the spring installed, you should feel a LOT of resistance when you compress the shock and it should return smoothly back to full extension on it's own.
When you're sure it's holding the nitrogen and oil with no leaks, re-install the spring and install on the bike.
Torque for top mounting bolt is 95nm, torque for lower bolt, (the hollow one with the grease fitting), is 55nm.
I used the plastic Kaw bracket to mount the reservoir on the frame behind the right rear passenger foot peg and mounting with a "P-clip" and an 8mm bolt. Took some "fiddling", but worked out OK.
So, before you drop $500, $800 or $1,000+ on an aftermarket shock, give this a try. For $100-$200 or so, you can get very close to the same result.
 

dearborn

Active Member
Local time
Yesterday, 21:31
Joined
Sep 29, 2015
Messages
111
Points
27
Age
70
Location
Dearborn Michigan USA
First Name
Doug
My Ride
1996 Thunderbird, 1975(ish) Norton Commando
To set "sag" had to crank pre-load on shock WAY up almost to end of threads on shock body. I'm no lightweight, about 215 lbs with full gear. Hard to get less than about 50mm of "sag", but rides/handles way better than stock Triumph unit. Current settings; Comp.= 3 clicks in from middle, rebound "2" These will change with more time on board.
 

dearborn

Active Member
Local time
Yesterday, 21:31
Joined
Sep 29, 2015
Messages
111
Points
27
Age
70
Location
Dearborn Michigan USA
First Name
Doug
My Ride
1996 Thunderbird, 1975(ish) Norton Commando
Using stock ZX9 spring, probably too soft.
 

dearborn

Active Member
Local time
Yesterday, 21:31
Joined
Sep 29, 2015
Messages
111
Points
27
Age
70
Location
Dearborn Michigan USA
First Name
Doug
My Ride
1996 Thunderbird, 1975(ish) Norton Commando
Took first long ride with a passenger/pillion since the shock swap; VAST improvement!!! Did about 150 miles with my 100lb daughter on the back. Setting proper "sag" is very important. No "hardtail"- like harshness; smooth, comfortable ride, even with Michigan's horrible "pavement motocross" roads. Still looking at going to heavier RaceTech spring and front upgrades. Winter is coming fast!
 

craigx

Member
Local time
Today, 02:31
Joined
Apr 21, 2017
Messages
9
Points
2
Age
69
Location
Hassocks,uk
First Name
Craig
My Ride
1995 thunderbird 900
I have read this thread with much interest as I have just stripped down a ZX9R shock with hose to fit on my TB. Like you I have found it difficult to find data on the shock, but Race Tech appears to be the best. What weight oil did you use.
 

dearborn

Active Member
Local time
Yesterday, 21:31
Joined
Sep 29, 2015
Messages
111
Points
27
Age
70
Location
Dearborn Michigan USA
First Name
Doug
My Ride
1996 Thunderbird, 1975(ish) Norton Commando
Used 7.5w BMW fork oil I had on hand. Seems fine. I suppose one could experiment with different viscosity oils, but you'd have to recharge nitrogen each time. Local Hon/Yam/Kaw/Suz dealer charges $20 per. (Beer money? "government job"?) Pretty messy, too. 7.5 seems OK, stock Kaw spring OK, too. Rides great with 100lb passenger, too, just crank up compression damping a couple of clicks. Bought a nifty pair of $20, used, Ebay, polished alloy, aftermarket "dog bones" from Kawasaki that allow adjusting ride height due to different length ZX9 shock vs OEM Triumph, works a treat. Just be sure to get the Kaw ZX9 shock with the remote reservoir on a hose. Don't buy the one with the attached reservoir that juts out at an angle. This WILL highlight the crappy OEM front fork springs. I weigh about 200lbs, so I bought RaceTech .85kg/mm, (vs OEM .467kg/mm stock fork springs), $110 + 15wt fork oil) Now, rides nice, handles better, less dive on braking.
 

craigx

Member
Local time
Today, 02:31
Joined
Apr 21, 2017
Messages
9
Points
2
Age
69
Location
Hassocks,uk
First Name
Craig
My Ride
1995 thunderbird 900
I always ride solo so I shall keep the Zx9 spring and see how that goes. Its now stripped down and waiting parts from Race tech. Not sure whether to use 7.5 or 10 w oil. I shall see what i can find.
 

dearborn

Active Member
Local time
Yesterday, 21:31
Joined
Sep 29, 2015
Messages
111
Points
27
Age
70
Location
Dearborn Michigan USA
First Name
Doug
My Ride
1996 Thunderbird, 1975(ish) Norton Commando
A number of places, including RaceTech can re-valve the shock according to your weight and type of use for $125-$175 or more. Involves the stack of discs on the damper rod. Since I had a spare "parts" donor ZX7 shock, (tried it but not happy), I played around a bit with the shim stack, ended up sticking with the stock ZX9 configuration. Best advice I can give; 1) use the ZX9 shock with the reservoir on a hose, $40 Ebay used. You'll need to rotate the connections a bit depending on where you mount the reservoir, I mounted mine to the frame above the R/H passenger footrest. RELEASE THE PRESSURE IN THE RESERVOIR BEFORE YOU BEGIN! It's gonna be messy! Squirts oil all over the place, cover with a shop rag! And "dry fit" your mounting point before you take the shock apart. 2) Measure the ride height BEFORE you disturb anything. 3) FIND A PLACE THAT WILL RECHARGE THE NITROGEN LOCALLY AND WILL NOT HOSE YOU FOR $$$$$! (because it'll probably take a couple tries before you get it "right") My local Hon/Kaw/Suz/Yam dealer will do it for $20, cash money. Not the $100-$125 the other Japan-o-rama dealer wanted. 4) Replace the bladder and any seals you can get, (RaceTech). The shock is 20 years old and it's gonna be leaky. Tutorials for dismantling the shock on YouTube, watch them all. Be careful, take your time, do it right, when grinding off the peen on the top of the shaft. Use a new nut, (good mom&pop hardware store will have 'em, NOT the "big box" store that only sells the Chinese junk. 5) Buy a pair of "adjustable" "dog bones" I found a nice pair of polished used ones on Ebay for $20. These will give you the ability to restore the proper ride height as the Kaw shock is about 14mm longer than the Triumph OEM. 6)Once you're done with the rear, you're gonna find out how crappy the stock front springs are, so budget the money to get those; I paid $109 off Ebay for RaceTech .85 springs and $15 for 15w fork oil. (Buy springs according to your weight) You're going to be happy with this. MUCH cheaper than dropping the HUGE bucks for aftermarket shock, you'll greatly improve BOTH the rear AND the front for around $200-$300.
 

craigx

Member
Local time
Today, 02:31
Joined
Apr 21, 2017
Messages
9
Points
2
Age
69
Location
Hassocks,uk
First Name
Craig
My Ride
1995 thunderbird 900
Thanks for the great advice. A bit too late for the dry fit option, but I shall try to fit before I pressurise the unit. That should allow me to slacken the hose connectors a bit to rotate them to where I need them.
 

craigx

Member
Local time
Today, 02:31
Joined
Apr 21, 2017
Messages
9
Points
2
Age
69
Location
Hassocks,uk
First Name
Craig
My Ride
1995 thunderbird 900
Fitted my rebuilt zx9 shock, filled it with 10w oil and pressurised it to 165 psi with air (to test operation) and it worked fine. A hugh improvement in the ride. I have kept the triumph "dog bones" so the bike has raised 30 to 40mm at the rear. Currently, i have the spring wound right up to try and compensate for the zx9s weaker spring. I think I shall back the spring right off and see if the extra sag will drop the height a bit. Job for tomorrow. Very pleased so far.
 
Premium

Support TriumphTalk by becoming a Premium Member.

 What You Get

Donate

 

 

Top Bottom